Method of pressing



Nov. 24, 1942. w. WHITEHEAD 2,302,824

- METHOD OF PRESSING Filed March 9, 1939 INVENTOR v BYfViHiar-n Whifeheqcl w W.

ATTORNEYS Patented Nov. 24, 1942 METHOD OF PnEssING WiIi iam Whitehea'd, Rye, N. Y., assignor to Celanese Corporation of America, a corporation of Delaware Applicationlviarch 9, 1939, Serial-No. 260,710

2 Claims.

This invention relates to a method of pressing textile fabrics and articles made of such fabrics, and. to pressing apparatus for carrying out the same.

An object of my and means for pressing textile products by which deleterious effects produced byformer methods are avoided. Other objects of my invention will appear from the following detailed description and drawing.

In the accompanying drawing The figure is an elevation partly in section of one form of apparatus for carrying out my invention.

In the steam pressing of suits and clothing,

more particularly in their manufacture, numerous pressing operations involve such equipment as the Hoffman presses. These presses shape and press the garment during and on completion of manufacture by exerting considerable mechanical pressure after and during the impregnating of the garment with steam substantially free of entrained Water. Mechanical pressures such as 150-250 lbs. per square inch are employed and steam brought to the machine at 60 lbs. pressure or more is employed.

For the existing trade, difficulties are encountered from the use of such pressures and steaming, in that flattening of the threads and filaments forming the fabric results and in turn this produces an undesirable glaze or sheen on the garment, more usually on the thicker portions of the garment in that greater pressure is generated at these places. Still further, where thicker places, such as double or triple layers, are situated immediately next to thinner places, a molding over of the fabric occurs undesirably. This glazing is more evident in some fabrics than others. For example, serges and gabardines glaze more readily than tabby weave fabrics. This glazing and molding-over can be minimized by such means as controlling the pressure and reducing the steam pressure or length of time of application of pressure and steam. Also in such fabrics as all worsted and woolens, the glazing may be partially removed by hand ironing of the garment skillfully with damp cloths imposed between the iron and the garment. However, the manufacture of garments, heretofore, has involved the processing of numerous fabrics simultaneously into garments and frequently more than one fabric comprises a garment and this results in complication and has left much to the individual skill of the operative.

Further, the processing into garments of fabrics invention is to provide method fabrics.

in the pressing of such fabrics or articles made therefrom, a mixture of steam with air or other inactive gas, the albove difficulties are overcome. In this way, higher pressures due to the presence of the air may be obtainedwithout a corresponding increase in temperature as necessarily is the case when pure steam is employed, since at a given pressure saturated steam has a fixed temperature, while when admixed with air, the temperature of steam at a given pressure is lower the temperature being lower, the greater the amount of air present. Moreover, due to the fact that the steam is admixed with air, less Water vapor is present in the treating or steaming atmosphere and this presents the added advantage of avoiding or reducing the condensation of moisture onto the article being pressed, which moisture tends to cause distortion after pressing to a fixed shape or size, that is, it tends to change on the subsequent drying out of the article.

While this invention is of general application to the pressing of textile fabrics or articles made therefrom, it is of particular advantage in the pressing of fabrics or articles made of yarns, filaments or fibers of thermoplastic material, such as synthetic resins, and organic derivatives of cellulose, such as cellulose acetate, cellulose propionate, cellulose butyrate or other organic ester of cellulose, and ethyl cellulose or benzyl cellulose or other cellulose ethers. It has been found particularly useful in solving the problem of pressing fabrics made of yarns made of staple fibers of cellulose acetate with or without some Wool fibers, which have been spun to simulate Wool, which fabrics are of such construction as to be used in the making of mens and womens suits or coats.

While for economy I employ air as the gas to be admixed with the steam, any other gas that is inert and uncondensibl at atmospheric condition's, such as nitrogen or carbon dioxide, may be employed.

The total pressure of the mixture of air and steam employed may be any suitable one, say from less than 30 to 120 or more lbs. per square inch above atmospheric. The proportion of air to steam may likewise be varied in order to obtain the required result depending on the nature of the fabric treated and the total pressure of the mixture used. Generally the use of from V2 to parts by volume of air per part of steam produces satisfactory results.

Any method of and apparatus for controllably mixing the air with steam may be employed. Conveniently, the compressed air and steam may be generated separately and apportioned and stored in a separate tank or storage vessel. Alternatively a storage vessel may be allowed to fill with steam and shut off when a pressure lower than that of the main steam supply is obtained and then this brought up to operating pressure by injection of compressed air.

The following is a description of one of the forms of apparatus for carrying out my invention that is shown on the drawing.

The press comprises a lower pressing member or platen l which is covered with felt or other soft fabric 2 to equalize pressures and which may be flat, curved or may have a complex shape according to the pressing and shaping desired. This lower platen may or may not be heated indirectly and may or may not have a mixture of steam fed thereto.

The upper pressing member or platen 3 is provided with a perforated face 4 through which the mixture of air and steam passes and this is preferably covered with a padding of cloth 5 to equalize mechanical pressures. The chamber 6 supplies the mixture of air and steam. The pressing member 3 is brought down onto the lower member 2 by means of the frame 1 which may be operated in any suitable manner.

The chamber 6 is supplied by the pipe 8 which connects with the trap 9 to which steam under pressure is conducted by pipe I0 and air under pressure by pipe ll. Any water [2 condensed in liquid form is removed from the trap 9 by petcock [3.

It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

1. A method of hot pressing fabric or fabric articles comprising yarns of an organic derivative of cellulose, which comprises applying pressure without heating on a fabric article to maintain the same in a predetermined form and setting said fabric article in said predetermined form by passing a mixture of steam and compressed gas, substantially free from condensed moisture, to and through said article while said article is so held, whereby said article is treated with a fluid containing steam, supplied at a pressure exceeding the vapor pressure of water at the temperature of the fluid.

2. A method of hot pressing fabric or fabric articles comprising yarns of cellulose acetate, which comprises applying pressure without heating on a fabric article to maintain the same in a predetermined form and setting said fabric article in said predetermined form by passing a mixture of steam and compressed gas, substantially free from condensed moisture, to and through said article while said article is so held, whereby said article is treated with a fluid containing steam, supplied at a pressure exceeding the vapor pressure of water at the temperature of the fluid.

WILLIAM WHITEHEAD. 

